Abstract: Components, systems, and methods for determining efficiency of an optical signal source in distributed communication systems are disclosed. Environmentally induced variations in the performance of optical sources used to convert electrical signals to optical signals (such as laser diodes) at the transmitters within the system can be evaluated in real time. Steps can be taken to compensate for these variations. The efficiency of the laser diode can be measured and provided to receivers in the distributed communication system. The receiver may use information related to the slope efficiency measurement to adjust the gain of the receiving amplifiers to provide desired adjustments to the gain. Thus, the receivers in the remote units (RU) receive information about the slope efficiency of the laser diodes at the head end equipment (HEE) and the HEE receives information about the slope efficiency of the laser diodes at the RU.

Abstract: Power management techniques in distributed communication systems in which the power available at a remote unit (RU) is measured and compared to the power requirements of the RU. Voltage and current are measured for two dummy loads at the RU and these values are used to solve for the output voltage of the power supply and the resistance of the wires. From these values, a maximum power available may be calculated and compared to power requirements of the RU.

Abstract: Frequency synchronizing a local oscillator in a remote unit in a distributed antenna system (DAS) used for frequency shifting communications signals based on a received digital pulse signal from a central unit. A remote unit receives a frequency shifted downlink communications signal and a reference pulse signal indicative of a frequency of a reference oscillator from a central unit. To recover the original signal, a mixing frequency signal generated by a local oscillator is used. To recover a signal having the same frequency as the original signal, the local oscillator should be the same or substantially the same frequency as the frequency used to create the frequency shifted version. A time difference signal indicating the frequency difference between the oscillators is calculated. A frequency adjustment signal is provided to the local oscillator based on the time difference signal to decrease the frequency difference between the oscillators.

Abstract: Frequency synchronizing a local oscillator in a remote unit in a distributed antenna system (DAS) used for frequency shifting communications signals based on a received digital pulse signal from a central unit. A remote unit receives a frequency shifted downlink communications signal and a reference pulse signal indicative of a frequency of a reference oscillator from a central unit. To recover the original signal, a mixing frequency signal generated by a local oscillator is used. To recover a signal having the same frequency as the original signal, the local oscillator should be the same or substantially the same frequency as the frequency used to create the frequency shifted version. A time difference signal indicating the frequency difference between the oscillators is calculated. A frequency adjustment signal is provided to the local oscillator based on the time difference signal to decrease the frequency difference between the oscillators.

Abstract: Distribution of management services in distributed antenna systems having a central unit and remote units configured to time-division multiplex (TDM) downlink and/or uplink management signals into time slots to form a TDM management frame signal. In this manner, collision will not occur between multiple management signals communicated over a common communications medium at the same time in the distributed antenna system. Collision detection and management mechanism can add design complexity, cost by requiring additional components, and require additional area on electronic boards. The TDM management frame signal may also be modulated at a carrier frequency before being combined with RF communications signals so that the combined signals are within a linear range of shared certain communications components to reduce cost and area.